I know all about fire-forming so that doesn't have to be discussed. But when creating a wildcat that includes minimizing case taper what has to be done? Does a cartridge diagram have to be drawn and sent to somewhere such as PT&G to get a reamer made? The round I'm wanting to work with includes necking down, shortening the neck, pushing the shoulder forward, blowing the shoulder to 40 degrees, and minimizing case taper. So what has to be done as far as the case taper goes?

Last edited by hhunter318; March 28, 2011 at 06:49 PM.
Reason: to clarify

Or look in their catalog and see what has already been done.
Odds are there is something out there in your caliber on your case with minimum body taper, steep shoulder, and short neck. Hmm, sounds like a Gibbs to me. That way you could order from stock. Wouldn't be the .299 hhunter magnumb but it would save time and money.

And then have another undersized reamer made (based on fired cartridges), so you can have dies made.

It's almost always cheaper to use an existing wildcat.
I really wanted my own wildcat chambered in the M77 I have at the gunsmith right now. But... I couldn't justify the cost of reamers, dies, etc. Since I settled on a 6mm bore size, I took the path of least resistance. I'm having a standard .243 Win chamber and throat cut, but the gunsmith is engraving the barrel with a custom chamber designation. And, I'm having Quality Cartridge make some custom-stamped brass. It'll be made to .243 Win SAAMI specs, but will have my custom head stamp on it.

Of course, you could do the same with other actual wildcats.

__________________"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."

Don't use chamber reamers for dies. The natural elasticity of brass requires a smaller reamer to be used on the dies. If you don't, you'll be lucky to get three firings before the cases will no longer chamber, and you'll have neck tension issues from day one (unless you use a neck sizing die from a cartridge that will allow your wildcat to enter the die body without being resized, but is short enough to allow neck sizing).

Short version:
You need two reamers: A chamber reamer, and a die body reamer.

__________________"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."

What i was brainstorming on was to take the original .416 Rigby case, neck down to .358, shorten the neck to .300, blow the shoulder forward to 40 degrees, and minimize the body taper. Is there anything close to that? It would have more capacity than the .338 Lapua since the Lapua was shortened from the original .416 case. The only downfall would be turning my own bullets due to the fact that nobody produces any .358 bullets for long range purposes. But this is no problem, my friend has a CNC lathe setup for turning bullets.

Look at page 5 under Alterations in Dave Manson's catalog to get cost ideas. Call and talk to Dave about your project for some idea of how best to approach it.

The reamer makers have some fill-in-the-blanks drawings for specifying the reamer. The computer program QuickDESIGN will let you start with an existing case (or create a new one) and modify it to your dimensions and automatically generate reamer drawings from your cartridge spec.

If you are going to look at making your own lower BC long range bullets, you'll be in for some fun, not the least of which will be choosing the twist rate for your rifling. That can be done with the stability calculator on the JBM ballistics site. You can design the bullet and cartridge in that QuickDESIGN program and export them to QuickLOAD to estimate starting load data.

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